Lever operated switch

ABSTRACT

A lever operated switch has a molded insulation body containing a snap action mechanism for moving movable contacts into and out of engagement with fixed contacts. Fixed contact terminals extend out of the body and a shield is snapped onto the body to protect the terminals. An insulation cover is snapped over the body and provides a mounting for a spring biased operating lever which has spurs that engage the body to limit inward pushing of the lever against the spring bias.

Umted States Patent 11 1 1111 3,777,007 Yeske 1 51 4, 1973 [5 LEVER OPERATED SWITCH 3,444,345 5/1969 Mackiewicz 200/168 0 1,870,072 8/1932 Seuffert 200/67 A [75] Lmls Yeske west Hartford 3,604,868 9/1971 Batcheller et al.. 200/67 G Conn- 2,688,057 8/1954 Slater 200/67 [73] Assignee: Arrow-Hart, lnc., Hartford, Conn.

Primary Examiner-David Smith, Jr. [22] Fled: 1972 Attorney-William F. Sonnekalb, Jr.

[21] Appl. N0.: 230,374

[57] ABSTRACT U.S CL n A C G A lever operated switch has a molded insulation 51 Int. (:1. 1110111 13/28 maining Snap mechanism mving Search I l I I I A able Contacts into and Out Of engagement fixed 66 R 168 168 contacts. Fixed contact terminals extend out of the 1 body and a shield is snapped onto the body to protect [56] References Cited the terminals. An insulation cover is snapped over the body and provides a mounting for a spring biased op- UNITED STATES PATENTS erating lever which has spurs that engage the body to i i limit inward pushing of the lever against the spring ac ewlcz 3,536,872 10/1970 Gilardenghi 200/67 G 3,165,574 1/ 1965 Carling 200/168 G 7 Claims, 7 Drawing Figures //1 f////////1 '///M'/////////V// LEVER OPERATED SWITCH This invention relates to electric switches and more particularly to lever operated over-center types of electric switches. However, several features of the invention are equally useful in electric switches operated by any other operating means.

Lever operated switches have been made and sold in large volume for many years, In some instances, they have had levers made of insulation material. Many lever operated switches have been assembled by having the lever inserted in a screw threaded neck from the inner end outwardly. Commonly, the levers have been pivoted on pins inserted laterally in the neck and lever. When not mounted on a transverse pin through the neck and the lever, the lever could be pushed inwardly far enough to overstress, damage or dislocate the switch parts and prevent proper operation of the switch mechanism.

It is an object of the invention to provide a lever operated switch having a plastic lever mountable in a neck from the inside end which has means to limit the inward movement or pressure of the lever after assembly on a switch housing or base.

When the terminals of the binding screw type used in electric switches and other wiring devices, particularly switches of the type in which the contact and wire terminal were unitary and were assembled by dropping into slots in the casing, base or housing, there was a tendency for the whole contact and terminal member to rotate when the binding screws were tightened onto the connector wire.

It is an object of this invention to provide a terminal structure with means to prevent twisting or rotating of the terminal as its binding screw is tightened.

Electric switches and wiring devices commonly have wire terminals on the bottom or sides frequently in recesses in the side corners of the switch housing or base. In use they tend to be covered with dust and are exposed to accidental brushing contact by personnel or tools.

It is an object of the invention to provide a protective cover or shield or insulation material which can be snapped into position over the bottom and side of the switch housing in position to cover the wire terminals and to protect them from accidental brushing contact and from accumulations of dust and dirt.

Other objects and advantages of the invention will occur to those skilled in the art as the invention is described in connection with the accompanying drawings.

In the drawings:

FIG. 1 is a side elevation'view of a switch embodying,

the invention with the protective shield omitted.

FIG. 2 is a longitudinal section view of the switch illustrated in FIG. 1, with the protective shield in place. FIG. 3 is an end elevation view partly broken away and partly in section of the switch shown in FIG. 1. FIG. 4 is a detailed view of the operating lever. FIG. 5 is a detailed view of one pair of the fixed contacts, a movable contact and its carrier and the operating yoke.

FIG. 6 is a perspective view of the protective shield. FIG. 7 is a fragmentary perspective view of one corner of the housing and mating stationary contact terminal portions.

Referring to the drawings, a molded insulation housing 10 is recessed and hollowed out to receive fixed and movable contacts and the mechanism for operating them. The housing has a closed bottom and has parallel side and end walls 12 and 14, respectively. In the example of the invention as shown, two pairs of fixed contacts 13a and 13b are positioned adjacent each side wall 12 in ,the bottom of the housing, and one contact 13a of each pair extends towards one end of the housing, while the other contact 1312 of that pair extends toward the opposite end of the housing. The contact surfaces of each pair are parallel and spaced laterally in position to be bridged by movable contacts 15. Each fixed contact has one terminal plate portion 16,16 which in the example shown has a binding screw 18 threaded into a tapped hole and positioned to be exposed through recesses in the four corners of the housing and to be available for attaching connector wires. However, the terminals may be of the spade type or of other type, if desired. The terminals preferably are stamped from sheet metal integrally with the fixed contact and are mounted conventionally in vertical .slots in the housing.

There are two movable contacts each being carried on an insulating plate 15. Each plate is positioned next to and movable parallel to one of the side walls of the housing. The carrier plates are mounted on the side arms of a swingable yoke 22, which has trunnions 22t seating in bearing recesses located centrally in the top edges of the side walls of the housing. Snap action is imparted to movement of the yoke by an over-center coiled compression spring 24, one end of which seats on the transverse part 21 of the yoke, while the opposite end presses against the end of an operating lever 40, whose structure is novel and will presently be described. The over-center spring, swingable yoke, fixed and movable contact structures are conventional in form and function.

When wires are connected to the terminal and the terminal screws 18 are tightened, there is a tendency to rotate the whole contact and terminal members thus moving the fixed contact within the housing out of the assembled and desired and necessary position. To prevent such turning, flat lugs 19 integral with the terminal plates are provided extending downwardly into recesses provided to receive the lugs 19 and formed in the bottom edge of the housing. The abutment of the lugs with the edges of the recesses prevents rotation of the terminal and the fixed contacts.

There are also provided tabs 16a and 16b on the stationary contact terminal portions 16. Tese tabs 16a are pressed out of the plane of the terminal plate and engage mating recesses 12a in the sidewalls 12 of the housing 10. These tabs 16a and 16b prevent rotation of the contacts 16 and 16 when tightening the terminal screws. It will be understood that the screws 18 may be subjected to torques as high as 7 inch pounds in normal tightening. Torques this high approach the limit that the screws can tolerate without mechanical failure and have caused problems with contacts in prior art switches.

The operating lever 40 is mounted pivotally for tilting of movement in the neck 35 of a snap-on cover designated generally by the numeral 30. The cover 30 is molded of insulating material with the top wall 31 covering the open top of the housing and with side walls 32 and end walls 34 which wrap around the top peripheral edges of the housing. The end walls 34 extend down the end wall of the housing only a short distance. In order to provide a snap on mounting of the cover which can be mounted on the housing without the need of screws, rivets or other separate fastening means, the side walls 32 of the cover are extended downward along the side walls of the housing and have openings 36 to receive one or more nubs 17 formed integrally with the housing and projecting laterally therefrom midway down the side walls. The upper edges of the nubs are inclined or beveled at 17a as they merge into the side walls, so that as the cover is pressed upon the housing, the side walls of the cover can slide upon and over the nubs until the lower margin of the opening 36 moves beyond the lower edges of the nubs 17 and the lower margins of the opening can thus snap under the edges of the nubs. For that purpose, the side walls of the cover are made thin enough to permit them to flex slightly and the insulating material of which the cover is made resilient enough to allow said flexing and snapping into latching position.

The sidewalls 32 are provided with projections 32a which extend into the opening 36 in the sidewalls 12. These projections 32a cooperate with a recess 17a in the nubs 17. The projections 32a are formed to provide a close fit with the recesses 17a and thereby prevent movement of the snap-on cover 30 in a direction parallel to the longitudinal dimension of the switch and to keep the cover 30 centered in case of excessive clearances 34a between the overlapping ends of the cover 30 and the switch housing. Opening 36 is formed with arcuate edge 36a on its edge engaging the nubs 17 to restrain the cover 30 from movement away from the switch housing. The arcuate edges 36a are formed so that the edge of the cover 30 must be deformed when assemblying the switch. This deformation in the edges results in a force tending to restore the opening to its original shape. This force is directed to hold the cover 30 tightly to the housing.

Extending up from the central cover is a hollow neck 35 preferably cylindrical and externally screw-threaded for conventional mounting and securement with a standard nut (not shown). The interior wall of the neck 35 is provided with two diametrically opposite channels 37 running lengthwise of the neck from a point near the top inwardly and downwardly. The upper or outer ends of the channels form seats for pivots 42, which extend radially outward of the operating lever 40 midway along its length. Channels 37 form passageways for the pivots 42 as the lever is inserted into the neck from the inside or bottom upwardly and outwardly. Since the over-center spring 24 presses against the lower or inner end of the lever 40, that pressure maintains the pivots 42 seated in the upper end of the channels 37.

Since the lever is mounted loosely in the neck and can be manually pressed inwardly against the pressure of the coiled compression spring, two spurs 44 are provided on the lever in diametrically opposite positions to prevent pressing the lever inwardly too far against the spring and overstressing or dislodging it or otherwise damaging or disarranging the operating assembly. The spurs 44 extend laterally in opposite directions from the lever lengthwise at points midway between pivots 42 and the inner end of the lever, in position to engaging the top surface of the housing when the lever is pressed inwardly. Viewing FIG. 2, if the lever is pressed inwardly against the pressure of the over-center spring 24, the progress of the inward movement of the lever will be stopped when the spurs engage the housing surface, thus protecting the operating mechanism.

Preferably, a pair of diametrically opposed lateral extensions 46 are provided adjacent the inner end of the lever against which the upper end of the spring comes to rest providing a seat for the upper end of the spring.

From the foregoing description, it will be observed that the switch is made entirely of molded insulating parts except for the contacts, over-center spring and the yoke. Except for the terminals, all parts are of insulation and assembled without the necessity of any tool or separate fastening means and avoiding the need to stamp any parts except the contacts and yoke. Also, the assembly costs are kept to a minimum because the contacts are easily dropped into place in the housing and the movable contacts when mounted upon their carrier and assembled upon the yoke, can be assembled as a unit. When the spring is positioned on the yoke, its upper end leans against the housing in position for the lever and cover to be snapped into assembled position with great facility and accuracy.

In order to cover the wire terminals and protect them and keep dust from them, a shield 50 made of molded insulation in hollow channel shaped form as shown in FIG. 6 is provided. Parallel side walls 51 and 52 of the shield extend up from a flat bottom wall 53 at opposite sides thereof in position to cover and overlie the terminals and terminal screws and the bared ends of the conductor wires which are connected to the binding screws when the shield is mounted on the bottom of the housing.

To enable quick mounting of the shield, a finger 54 is provided at each end of the bottom wall 53 extending perpendicularly thereto. The finger is narrow and thin enough to possess resilience sufflcient to permit it to flex slightly. Each finger has a latch nose 55 or projection tapering from a shoulder perpendicular to the finger to the end of the finger, so that as the shield is pressed into place, the tapered portion of the latch will slide along the end of the wall of the housing until reaching a recess 56 that is provided in the end wall of the housing, whereupon the latch may snap into the recess holding the shield in place. The shield can be easily removed by flexing of the fingers 54 away from the housing walls and moving the shield downwardly when desired.

Many modifications within the scope of the invention will occur to those skilled in the art. Therefore, the invention is not limited to the specific form and details of the parts as described and illustrated.

I claim:

1. In an electric switch, a casing having a top wall and a recess, an operating mechanism including a coiled compression spring in said recess, movable contact means including a swingable yoke actuated by said spring between two at-rest positions, fixed contact means in said casing engageable and disengageable by said movable contact means, a solid tiltable operating lever, supporting means mounted over and secured to said casing, a pivot seat for pivotally supporting said lever, said spring exerting a bias on said lever lengthwise to hold the lever against said seat, said lever being lengthwise movable within said supporting means against said bias, and spurs laterally projecting from said lever and engaging said top wall to limit the antibias lengthwise movement of said lever.

2. The combination as claimed in claim 1 including contact rotation limiting means for limiting the rotational movement of said fixed contact means.

3. In an electric switch, a casing having a recess, an operating mechanism including a coiled compression spring in said recess, movable contact means actuated by said spring between two at-rest positions, fixed contact means in said casing engageable and disengageable by said movable contact means, cover means mounted on said casing and having a hollow extension, said extension having internal channel means lengthwise of said extension with a bearing seat at one end, a solid tiltable operating lever insertable outwardly through said extension and having bearing means slidable along said channel means, said spring exerting a bias on said lever lengthwise to hold the lever against said seat, and means laterally projecting from said lever and engaging means on said casing limiting lengthwise movement of said lever into the casing.

4. The combination as claimed in claim 12 in which said casing has a top wall adjacent said recess, and said limiting means comprises spurs laterally projecting from said lever and engageable with said top wall.

5. The combination as claimed in claim 3 including contact rotation limiting means for limiting the rotational movement of said fixed contact means.

6. A rectangular molded insulation housing for an electric switch, a plurality of fixed contact members mounted within said housing, movable contact means for connecting and disconnecting said fixed contact members, an operating member extending into said housing to operate said movable contact means, wire terminal members connected to said fixed contact members and extending through said housing and exposed for connection of conductor wires thereto, said housing having recesses in at least one side wall of said housing in which said terminal members are located, in combination with a snap-on molded insulation shield member cooperating with said housing and having bottom and side walls, at least one side wall overlying the side wall of said housing and overlying said terminal members protecting them from accidental contact and from dust, and flexible fingers on said shield member extending adjacent the end walls of said housing and of less width than said end walls and engageable in recesses in said end walls to maintain said shield in said overlying position but readily disengageable for removal of said shield member.

7. The invention as claimed in claim 6 including contact rotation limiting means for limiting the rotational movement of said fixed contact means.

@ 2 3 UNITED STATES PATENT OFFICE CERTIFECATE OF CORRECTION Patent No. 777,087 Dated December 4 1973 Inventofls) Louis A. Yeske i It is certified that error appears in the above-identified patent and that said Letters Patent are hereby correeted as shown below:

f'column 5, line 20 (Claim 4), "12" shou ld be 3 Signed and sealed this 6th day of August 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. "C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. In an electric switch, a casing having a top wall and a recess, an operating mechanism including a coiled compression spring in said recess, movable contact means including a swingable yoke actuated by said spring between two at-rest positions, fixed contact means in said casing engageable and disengageable by said movable contact means, a solid tiltable operating lever, supporting means mounted over and secured to said casing, a pivot seat for pivotally supporting said lever, said spring exerting a bias on said lever lengthwise to hold the lever against said seat, said lever being lengthwise movable within said supporting means against said bias, and spurs laterally projecting from said lever and engaging said top wall to limit the anti-bias lengthwise movement of said lever.
 2. The combination as claimed in claim 1 including contact rotation limiting means for limiting the rotational movement of said fixed contact means.
 3. In an electric switch, a casing having a recess, an operating mechanism including a coiled compression spring in said recess, movable contact means actuated by said spring between two at-rest positions, fixed contact means in said casing engageable and disengageable by said movable contact means, cover means mounted on said casing and having a hollow extension, said extension having internal channel means lengthwise of said extension with a bearing seat at one end, a solid tiltable operating lever insertable outwardly through said extension and having bearing means slidable along said channel means, said spring exerting a bias on said lever lengthwise to hold the lever against said seat, and means laterally projecting from said lever and engaging means on said casing limiting lengthwise movement of said lever into the casing.
 4. The combination as claimed in claim 12 in which said casing has a top wall adjacent said recess, and said limiting means comprises spurs laterally projecting from said lever and engageable with said top wall.
 5. The combination as claimed in claim 3 including contact rotation limiting means for limiting the rotational movement of said fixed contact means.
 6. A rectangular molded insulation housing for an electric switch, a plurality of fixed contact members mounted within said housing, movable contact means for connecting and disconnecting said fixed contact members, an operating member extending into said housing to operate said movable contact means, wire terminal members connected to said fixed contact members and extending through said housing and exposed for connection of conductor wires thereto, said housing having recesses in at least one side wall of said housing in which said terminal members are located, in combination with a snap-on molded insulation shield member cooperating with said housing and having bottom and side walls, at least one side wall overlying the side wall of said housing and overlying said terminal members protecting them from accidental contact and from dust, and flexible fingers on said shield member extending adjacent the end walls of said housing and of less width than said end walls and engageable in recesses in said end walls to maintain said shield in said overlying position but readily disengageable for removal of said shield member.
 7. The invention as claimed in claim 6 including contact rotation limiting means for limiting the rotational movement of said fixed contact means. 